29pcs Cobalt Drill Bits Set, M35 Drill Bits for Cutting Hard Metal Hardened. 4X LIFESPAN MATERIAL – Made from industrial grade M35 high-speed steel with 5% cobalt provides hardness for wear resistance, withstands max 1100 degreeF, for much faster cutting and extra longer life span when compared with an average HSS drill bit. MULTIPLE APPLICATION – Perfectly suitable for drilling hard metal such as stainless steel, cast iron, high temperature alloy, titanium alloy. Moreover, they can also be applied to cutting duroplasts, wood and some other soft materials. SMOOTHLY DRILLING – The split point design increases the cutting edge on the tip, and the blunter 135° angle means more of the cutting edge touches the surface sooner. The grooves on the sides of the bits’ twisted shanks will bring metal shavings up and out of the hole as you drill. EFFICIENCY – Working with stationary drill ensures better finish on chamfers but they can be used with hand drills as well for countersinking in any hard or soft metal and any type of wood. 29PCS DRILL BIT SET – Metal index case with size chart for easy bit access and identification. Includes drill bit sizes from 1/16 to 1/2 inch increments.